Getting array back from map

Hey

I'm wondering how to get array back that I placed in map as
Map<ArrayList<String>, ...>

When I try to print map.keySet() I get
[[string, string, string]]

It's kinda weird that when I try to StringTokenizer it then I get only object that object gibberish
[Ljava.lang.String;...

I would like to get my array back as array or in some kind of sequence (like I would get on tokenizer)

What about looping through the set returned by map.keySet ?

Your keys are arrays (which may or may not be what you really want), and the key set will be a set of arrays--that appears to be what you're getting.

Things like "[Ljava.lang.String..." aren't "gibberish"--that's a default toString() method, and is an array of Strings.

Yes it's set of arrays. Now how could I read this array

I was just wondering that when I print it as toString it prints me an array, when I try to tokenizer it, which could be one way to use this non-array array, it thing just messes thing up.


Oh and yes it is gibberish if it isn't meant for human to understand

There's no "non-array array"--it's an array. You have a set of arrays. Did you see Christophe's answer? Get the array from the key set. Then do whatever you want with it.

(And it *is* designed for a human to read; see these examples--sorry I can't find the correct reference off the top of my head.)

Sounds good. How can I get it from set?

Jukka Kuusamo wrote:Sounds good. How can I get it from set?

Take a look at the java.util.Set API, which will likely lead you to the java.util.Iterator API.

Henry

On a side note, it is a bad idea to use any highly mutable object (like Lists, Sets, Collections) as keys of a Map. The return values of the methods used to look them up again (hashCode + equals for (Linked)HashMap, compareTo / Comparator.compare for TreeMap) are very likely to change, therefore making it impossible to use methods like get, containsKey and other similar methods. It even allows you to use the very same object as two different keys. For instance:
Map<List<String>,String> map = new HashMap<List<String>,String>(); List<String> list = new ArrayList<String>(); list.add("Hello"); map.put(list, "Hello"); list.add("World"); System.out.println(map.get(list)); // null map.put(list, "World"); // does not overwrite the previous entry but adds a new one System.out.println(map);

Well now I got it. I didn't really know how to walk though ArrayList.